Coral-like {SiW10Mn2}-based Mn-MOFs: Facile fabrication with high electrochemical capacitor performance

Abstract

Developing advanced electrode material with high specific capacitance and long-time cycling stability is significant in supercapacitors domain. Polyoxometalates (POMs) and metal-organic frameworks (MOFs) possessing excellent multi-electron redox properties and controllable surface area, respectively, should be attractive candidates for efficient electrode materials. In this paper, we report a novel coral-like POMs-based Mn-MOFs, i.e. [Mn2 (BTC)4/3(H2O)6]6[K8(SiW10Mn2Cl4O36)] ({SiW10Mn2}@Mn-MOF), fabricating via a straightforward grinding method and explore its electrochemical capacitor performance. The as-prepared {SiW10Mn2}@Mn-MOF shows outstanding specific capacitance (211.0 ​F ​g−1) and long-time cycling stability (96.0% after 5000 cycles), resulting from the synergistic effect among POMs and Mn-MOF. Furthermore, the fully aqueous symmetric supercapacitor (ASS) assembled using {SiW10Mn2}@Mn-MOF as electrode and nickel foam as current collector also exhibits a satisfactory energy density (1.2 ​Wh kg−1 at 211.7 ​W ​kg −1). The synthesis of coral-like POMs-based Mn-MOFs, will guide the development of new and promising electrode materials for supercapacitor.